Hydroelectricity

Hydroelectricity (also known as 'hydro') is a well-developed renewable energy technology that has been around for more than a century.

Hydro uses flowing water to spin a turbine connected to a generator that produces electricity. The amount of electricity generated depends on the volume of water and the height of the water above the turbine.

Large hydroelectric power stations need dams to store the water required to produce electricity. These dams are often built to hold irrigation or drinking water, and the power station is included in the project to ensure maximum value is extracted from the water.

Hydroelectricity does not actually consume any water, as all the water is returned to the river after use.

While hydro plants can have very large capacities, the amount of electricity they generate can vary markedly from year to year depending on rainfall and electricity demand. Hydro can provide both baseload and peakload electricity, and hydro generators can start up and supply maximum power within 90 seconds.

Smaller hydroelectric power stations (called mini or micro hydro) do not generally need dams but rely on naturally flowing water such as streams. These provide a good source of power and are often used as stand-alone systems not connected to the main electricity grid.

Hydroelectricity in Australia: 2016 in focus

Hydro power currently accounts for 42.3 per cent of the renewable electricity produced in Australia. The majority of this energy is generated by Tasmania's hydroelectric plants and the Snowy River Hydro Scheme in New South Wales.

Thanks to higher rainfall in key catchments compared to 2015, hydro power rebounded to more typical levels in 2016. Despite low levels of water storage in Tasmania in the first part of 2016, above average falls from May resulted in high levels of generation at many key Tasmanian hydropower stations.

The future of hydroelectricity in Australia

The review of Australia's power system security by Chief Scientist Alan Finkel includes consideration of Australia's future pumped hydro storage potential and how this could complement the development of other renewable energy technologies.

The Australian National University will map Australia's pumped-hydro storage potential, with support provided by the the Australian Renewable Energy Agency. The project will research integration of technology into the electricity grid so that it can provide large-scale, reliable clean energy storage at national, state and regional levels.

In early 2017, Prime Minister Malcolm Turnbull announced a planned expansion of the Snowy Hydro Scheme to include pumped hydro capability.